Reference signal transmission method, device, and system

ABSTRACT

Embodiments of the present application provide a reference signal transmission method, a device, and a system. The method includes: determining, by a first device, at least one reference signal generation sequence corresponding to at least one frequency-domain resource group that is on a symbol carrying a reference signal and that is used to send the reference signal, where one frequency-domain resource group is corresponding to one reference signal generation sequence; and generating, by the first device, the reference signal based on the at least one reference signal generation sequence, and mapping the reference signal to a time-frequency resource whose time domain is the symbol and whose frequency domain is the at least one frequency-domain resource group.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is a continuation of U.S. patent application Ser. No.16/154,557, filed on Oct. 8, 2018, which is a continuation ofInternational Application No. PCT/CN2017/072916, filed on Feb. 4, 2017,which claims priority to Chinese Patent Application No. 201610218110.4,filed on Apr. 8, 2016 and Chinese Patent Application No. 201610867115.X,filed on Sep. 29, 2016. All of the aforementioned patent applicationsare hereby incorporated by reference in their entireties

TECHNICAL FIELD

Embodiments of the present application relate to the communicationsfield, and more specifically, to a reference signal transmission method,a device, and a system.

BACKGROUND

A 5th generation (5G) network is also referred to as NR (New Radio/RAT).The International Telecommunications Union (ITU) defines three types ofservices in expectations and requirements of 5G: an enhanced mobilebroadband (eMBB) service, an ultra-reliable and low latencycommunications (URLLC) service, and a massive machine type communication(mMTC) service. An expected latency in the URLLC service is extremelyshort, and a minimum latency is merely 1 ms. Because the URLLC servicehas an urgent latency, when data arrives, resources need to beimmediately scheduled and allocated without waiting. In addition, theURLLC service has a high reliability requirement, usually requiringultra-high reliability of 99.999%.

In the prior art related to embodiments of the present application, inan uplink multi-user multiple-input multiple-output (UL MU-MIM0) systemin Long Term Evolution (LTE), defining, in a code division multiplexing(CDM) manner, mutually orthogonal demodulation reference signals (DMRS)on a same time-frequency resource is allowed, so as to implementreference signal (RS) resource multiplexing among paired user equipments(UE) in UL MU-MIM0. If the paired UEs in UL MU-MIM0 occupy differentbandwidths and the bandwidths partly overlap, different UEs usereference signal base sequences of different lengths. In this case,orthogonality among RSs of different UEs cannot be ensured by using onlycyclic shifts of the base sequences. A similar problem also exists in ascenario in which paired UEs in a downlink multi-user multiple-inputmultiple-output (DL MU-MIIVIO) system occupy different bandwidths, andthe bandwidths partly overlap, and in a scenario of anorthogonal/quasi-orthogonal pilot design among different cells. How toensure orthogonality among RSs of different UEs in different bandwidthscenarios to implement RS resource multiplexing of a plurality of UEs isa technical problem to be resolved in the embodiments of the presentapplication.

SUMMARY

Embodiments of the present application provide a reference signaltransmission method, a device, and a system, to implement RS resourcemultiplexing of a plurality of UEs.

According to a first aspect, a reference signal transmission method isprovided, where the method includes: determining, by first userequipment, at least one base sequence corresponding to at least onefrequency-domain resource group that is on a symbol carrying a referencesignal and that is used to send the reference signal, where onefrequency-domain resource group is corresponding to one base sequence,and each frequency-domain resource group includes a plurality ofsubcarriers that have a same quantity; and generating, by the first userequipment, the reference signal based on the at least one base sequence,and mapping the reference signal to a time-frequency resource whose timedomain is the symbol and whose frequency domain is the at least onefrequency-domain resource group.

In one embodiment, if both the first user equipment and second userequipment generate reference signal sequences on a thirdfrequency-domain resource group, cyclic shifts used by the first userequipment and the second user equipment to generate the reference signalsequences based on a third base sequence are different, where the thirdfrequency-domain resource group is one of the at least onefrequency-domain resource group, and the third base sequence is a basesequence corresponding to the third frequency-domain resource group.

In one embodiment, specific implementation of determining, by first userequipment, at least one base sequence corresponding to at least onefrequency-domain resource group that is on a symbol carrying a referencesignal and that is used to send the reference signal is: determining, bythe first user equipment, a first base sequence corresponding to a firstfrequency-domain resource group, and determining a second base sequencecorresponding to a second frequency-domain resource group; and specificimplementation of generating, by the first user equipment, the referencesignal based on the at least one base sequence, and mapping thereference signal to a time-frequency resource whose time domain is thesymbol carrying the reference signal and whose frequency domain is theat least one frequency-domain resource group is: generating, by thefirst user equipment, a first reference signal sequence of the referencesignal based on the first base sequence, and mapping the first referencesignal sequence to a time-frequency resource whose time domain is thesymbol and whose frequency domain is the first frequency-domain resourcegroup; and generating, by the first user equipment, a second referencesignal sequence of the reference signal based on the second basesequence, and mapping the second reference signal sequence to atime-frequency resource whose time domain is the symbol and whosefrequency domain is the second frequency-domain resource group.

In one embodiment, a cyclic shift used by the first user equipment togenerate the first reference signal sequence is the same as a cyclicshift used to generate the second reference signal sequence.

In one embodiment, the cyclic shift is notified by a base station to thefirst user equipment; or the cyclic shift is determined by the firstuser equipment based on a configuration parameter, where theconfiguration parameter includes one or more of a userequipment-specific configuration parameter, a time domain-specificconfiguration parameter, a cell-specific configuration parameter, or afrequency domain-specific configuration parameter that are of the firstuser equipment, and the configuration parameter cannot include only thecell-specific configuration parameter or the frequency domain-specificconfiguration parameter.

In one embodiment, a correspondence between the frequency-domainresource group and the base sequence is pre-defined, or a correspondencebetween the frequency-domain resource group and the base sequence issent by the base station to the first user equipment.

According to a second aspect, user equipment is provided, configured toperform the method in any one of the first aspect or the possibleimplementations of the first aspect.

Specifically, the user equipment may include units configured to performthe method in any one of the first aspect or the possibleimplementations of the first aspect.

According to a third aspect, another user equipment is provided,including a memory and a processor, where the memory is configured tostore an instruction, and the processor is configured to execute theinstruction stored in the memory, and executes the instruction stored inthe memory, so that the processor performs the method in any one of thefirst aspect or the possible implementations of the first aspect.

According to a fourth aspect, a computer readable storage medium isprovided, configured to store a computer program, and the computerprogram includes an instruction used to perform the method in any one ofthe first aspect or the possible implementations of the first aspect.

According to a fifth aspect, another reference signal transmissionmethod is provided, where the method includes: receiving, by userequipment, downlink control signaling sent by a base station, where thedownlink control signaling is used to indicate a frequency-domainresource group that is on a symbol carrying a reference signal and thatis used by the user equipment to send the reference signal; andgenerating, by the user equipment, a reference signal sequence, andmapping the reference signal sequence to a time-frequency resource whosetime domain is the symbol and whose frequency domain is thefrequency-domain resource group.

In one embodiment, the method further includes: determining, by the userequipment, the frequency-domain resource group based on afrequency-domain resource occupied by the user equipment and afrequency-domain comb, where the frequency-domain resource groupincludes a plurality of evenly spaced comb teeth (one comb tooth is onesubcarrier).

In one embodiment, the frequency-domain comb is used to obtain onesubcarrier at an interval of N subcarriers from a continuousfrequency-domain resource, to obtain a plurality of evenly spaced combteeth (subcarriers).

In one embodiment, a comb structure may include M consecutivesubcarriers obtained at an interval of N subcarriers, where intervalsbetween a plurality of M subcarriers are equal.

According to a sixth aspect, user equipment is provided, configured toperform the method in any one of the fifth aspect or the possibleimplementations of the fifth aspect.

Specifically, the user equipment may include units configured to performthe method in any one of the fifth aspect or the possibleimplementations of the fifth aspect.

According to a seventh aspect, another user equipment is provided,including a memory and a processor, where the memory is configured tostore an instruction, and the processor is configured to execute theinstruction stored in the memory, and executes the instruction stored inthe memory, so that the processor performs the method in any one of thefifth aspect or the possible implementations of the fifth aspect.

According to an eighth aspect, a computer readable storage medium isprovided, configured to store a computer program, and the computerprogram includes an instruction used to perform the method in any one ofthe fifth aspect or the possible implementations of the fifth aspect.

According to a ninth aspect, another reference signal communicationmethod is provided, where the method includes: determining, by userequipment, a frequency-domain resource that carries a reference signalof the user equipment, where the frequency-domain resource issubcarriers that are distributed at equal intervals in frequency domain,and the reference signal is used for data channel demodulation; andsending, by the user equipment, the reference signal to a base stationon the frequency-domain resource, or receiving, by the user equipment onthe frequency-domain resource, the reference signal sent by a basestation.

In one embodiment, the determining, by user equipment, afrequency-domain resource that carries a reference signal of the userequipment includes: determining, by the user equipment based on a firstparameter, the frequency-domain resource that carries the referencesignal of the user equipment, where the first parameter includes atleast one of the following parameters: a user equipment-specificparameter, a time domain-specific parameter, a cell-specific parameter,a frequency domain-specific parameter, or a first configurationparameter from the base station, where the first configuration parameterfrom the base station is configuration information sent by the basestation to the user equipment, and the configuration information is usedby the user equipment to determine the frequency-domain resource thatcarries the reference signal of the user equipment.

In one embodiment, the first configuration parameter from the basestation includes at least one of the following parameters: an antennaport, a frequency domain start location of a transmission comb, atransmission comb index, or a subcarrier set index.

In one embodiment, the user equipment determines, based on a secondparameter, a cyclic shift and/or an orthogonal cover code used for asequence of the reference signal, where the second parameter includes atleast one of the following parameters: the user equipment-specificparameter, the time domain-specific parameter, the cell-specificparameter, the frequency domain-specific parameter, or a secondconfiguration parameter from the base station, where the secondconfiguration parameter from the base station is configurationinformation sent by the base station to the user equipment, and theconfiguration information is used by the user equipment to determine thecyclic shift and/or the orthogonal cover code used for the sequence ofthe reference signal.

In one embodiment, the second configuration parameter from the basestation includes at least one of the following parameters: the antennaport, the frequency domain start location of the transmission comb, thetransmission comb index, the subcarrier set index, a cyclic shiftidentifier, or an orthogonal cover code identifier.

According to a tenth aspect, user equipment is provided, configured toperform the method in any one of the ninth aspect or the possibleimplementations of the ninth aspect.

According to an eleventh aspect, another user equipment is provided,including a memory and a processor, where the memory is configured tostore an instruction, and the processor is configured to execute theinstruction stored in the memory, and executes the instruction stored inthe memory, so that the processor performs the method in any one of theninth aspect or the possible implementations of the ninth aspect.

According to a twelfth aspect, a computer readable storage medium isprovided, configured to store a computer program, where the computerprogram includes an instruction used to perform the method in any one ofthe ninth aspect or the possible implementations of the ninth aspect.

According to a thirteenth aspect, another reference signal transmissionmethod is provided, where the method includes: sending, by a basestation, downlink control signaling to user equipment, where thedownlink control signaling is used to indicate a frequency-domainresource group that is on a symbol carrying a reference signal and thatis used by the user equipment to send the reference signal; andreceiving, by the base station, the reference signal sent by the userequipment on the frequency-domain resource group.

In one embodiment, the downlink control signaling carries afrequency-domain comb index, and the frequency-domain comb index is usedto determine the frequency-domain resource group in combination with afrequency-domain resource of the user equipment, where thefrequency-domain resource group includes a plurality of evenly spacedcomb teeth (one comb tooth is one sub carrier).

In one embodiment, the frequency-domain comb is corresponding to onetype of base sequence, and the frequency-domain comb index is furtherused by the user equipment to determine a base sequence used to generatea reference signal sequence, and there may be a multiple-to-one orone-to-one correspondence between the frequency-domain comb and the basesequence.

In one embodiment, the base station sends the downlink control signalingby using a UE-specific message or the like.

According to a fourteenth aspect, a base station is provided, configuredto perform the method in any one of the thirteenth aspect or thepossible implementations of the thirteenth aspect.

Specifically, the base station may include units configured to performthe method in any one of the thirteenth aspect or the possibleimplementations of the thirteenth aspect.

According to a fifteenth aspect, another base station is provided,including a memory and a processor, where the memory is configured tostore an instruction, and the processor is configured to execute theinstruction stored in the memory, and executes the instruction stored inthe memory, so that the processor performs the method in any one of thethirteenth aspect or the possible implementations of the thirteenthaspect.

According to a sixteenth aspect, a computer readable storage medium isprovided, configured to store a computer program, where the computerprogram includes an instruction used to perform the method in any one ofthe thirteenth aspect or the possible implementations of the thirteenthaspect.

According to a seventeenth aspect, another reference signalcommunication method is provided, where the method includes: sending, bya base station, downlink control signaling to user equipment, where thedownlink control signaling is used to instruct the user equipment todetermine a frequency-domain resource that carries a reference signal ofthe user equipment, the frequency-domain resource is subcarriers thatare distributed at equal intervals in frequency domain, and thereference signal is used for data channel demodulation; sending, by thebase station, the reference signal to the user equipment on thefrequency-domain resource, or receiving, by the base station on thefrequency-domain resource, the reference signal sent by the userequipment.

In one embodiment, the downlink control signaling carries a firstparameter, where the first parameter is used to determine thefrequency-domain resource that carries the reference signal of the userequipment, and the first parameter includes at least one of thefollowing parameters: a user equipment-specific parameter, a timedomain-specific parameter, a cell-specific parameter, a frequencydomain-specific parameter, or a first configuration parameter from thebase station, where the first configuration parameter from the basestation is configuration information sent by the base station to theuser equipment, and the configuration information is used by the userequipment to determine the frequency-domain resource that carries thereference signal of the user equipment.

In one embodiment, the first configuration parameter from the basestation includes at least one of the following parameters: an antennaport, a frequency domain start location of a transmission comb, atransmission comb index, or a subcarrier set index.

In one embodiment, the downlink control signaling carries a secondparameter, where the second parameter is used to determine a cyclicshift and/or an orthogonal cover code used for a sequence of thereference signal, and the second parameter includes at least one of thefollowing parameters: the user equipment-specific parameter, the timedomain-specific parameter, the cell-specific parameter, the frequencydomain-specific parameter, or a second configuration parameter from thebase station, where the second configuration parameter from the basestation is configuration information sent by the base station to theuser equipment, and the configuration information is used by the userequipment to determine the cyclic shift and/or the orthogonal cover codeused for the sequence of the reference signal.

In one embodiment, the second configuration parameter from the basestation includes at least one of the following parameters: the antennaport, the frequency domain start location of the transmission comb, thetransmission comb index, the subcarrier set index, a cyclic shiftidentifier, or an orthogonal cover code identifier.

According to an eighteenth aspect, a base station is provided,configured to perform the method in any one of the seventeenth aspect orthe possible implementations of the seventeenth aspect.

Specifically, the base station may include units configured to performthe method in any one of the seventeenth aspect or the possibleimplementations of the seventeenth aspect.

According to a nineteenth aspect, another base station is provided,including a memory and a processor, where the memory is configured tostore an instruction, and the processor is configured to execute theinstruction stored in the memory, and executes the instruction stored inthe memory, so that the processor performs the method in any one of theseventeenth aspect or the possible implementations of the seventeenthaspect.

According to a twentieth aspect, a computer readable storage medium isprovided, configured to store a computer program, where the computerprogram includes an instruction used to perform the method in any one ofthe seventeenth aspect or the possible implementations of theseventeenth aspect.

According to a twenty-first aspect, a reference signal transmissionmethod is provided, where the method includes: determining, by a firstdevice, at least one reference signal generation sequence correspondingto at least one frequency-domain resource group that is on a symbolcarrying a reference signal and that is used to send the referencesignal, where one frequency-domain resource group is corresponding toone reference signal generation sequence; and generating, by the firstdevice, the reference signal based on the at least one reference signalgeneration sequence, and mapping the reference signal to atime-frequency resource whose time domain is the symbol and whosefrequency domain is the at least one frequency-domain resource group.

In one embodiment, when both the first device and a second device mapreference signals to a time-frequency resource whose time domain is thesymbol and whose frequency domain is a third frequency-domain resourcegroup, cyclic shifts or orthogonal cover codes used by the first deviceand the second device to generate the reference signals based on a thirdreference signal generation sequence are different, where the thirdfrequency-domain resource group is one of the at least onefrequency-domain resource group, and the third reference signalgeneration sequence is a reference signal generation sequencecorresponding to the third frequency-domain resource group.

In one embodiment, the cyclic shift or the orthogonal cover code isdetermined by the first device based on a first parameter set, andparameters in the first parameter set include one or more of a userequipment-specific parameter, a time domain-specific parameter, acell-specific parameter, a network side device-specific parameter, afrequency domain-specific parameter, a network side configurationparameter, or a combination parameter, where the combination parameteris a combination of a plurality of parameters in the userequipment-specific parameter, the time domain-specific parameter, thecell-specific parameter, the network side device-specific parameter, thefrequency domain-specific parameter, and the network side configurationparameter; or when the first device is user equipment, the cyclic shiftor the orthogonal cover code is notified to the first device by anetwork side device connected to the first device.

In one embodiment, when both the first device and a second device mapreference signals to a time-frequency resource whose time domain is thesymbol and whose frequency domain is a third frequency-domain resourcegroup, a reference signal generation sequence corresponding to the firstdevice on the third frequency-domain resource group is different from areference signal generation sequence corresponding to the second deviceon the third frequency-domain resource group.

In one embodiment, specific implementation of determining, by a firstdevice, at least one reference signal generation sequence correspondingto at least one frequency-domain resource group that is on a symbolcarrying a reference signal and that is used to send the referencesignal is: determining, by the first device, a first reference signalgeneration sequence corresponding to a first frequency-domain resourcegroup, and determining a second reference signal generation sequencecorresponding to a second frequency-domain resource group; and specificimplementation of generating, by the first device, the reference signalbased on the at least one reference signal generation sequence, andmapping the reference signal to a time-frequency resource whose timedomain is the symbol carrying the reference signal and whose frequencydomain is the at least one frequency-domain resource group is:generating, by the first device, a first reference signal sequence ofthe reference signal based on the first reference signal generationsequence, and mapping the first reference signal sequence to atime-frequency resource whose time domain is the symbol and whosefrequency domain is the first frequency-domain resource group; andgenerating, by the first device, a second reference signal sequence ofthe reference signal based on the second reference signal generationsequence, and mapping the second reference signal sequence to atime-frequency resource whose time domain is the symbol and whosefrequency domain is the second frequency-domain resource group.

In one embodiment, the reference signal generation sequence isdetermined by the first device based on a second parameter set, andparameters in the second parameter set include one or more of a userequipment-specific parameter, a time domain-specific parameter, acell-specific parameter, a network side device-specific parameter, afrequency domain-specific parameter, a network side configurationparameter, or a combination parameter, where the combination parameteris a combination of a plurality of parameters in the userequipment-specific parameter, the time domain-specific parameter, thecell-specific parameter, the network side device-specific parameter, thefrequency domain-specific parameter, and the network side configurationparameter; or a correspondence between the frequency-domain resourcegroup and the reference signal generation sequence is pre-defined, orwhen the first device is user equipment, a correspondence between thefrequency-domain resource group and the reference signal generationsequence is sent to the first device by a network side device connectedto the first device.

According to a twenty-second aspect, a device is provided, configured toperform the method in any one of the twenty-first aspect or the possibleimplementations of the twenty-first aspect.

Specifically, the device may include units configured to perform themethod in any one of the twenty-first aspect or the possibleimplementations of the twenty-first aspect.

According to a twenty-third aspect, another device is provided,including a memory and a processor, where the memory is configured tostore an instruction, and the processor is configured to execute theinstruction stored in the memory, and executes the instruction stored inthe memory, so that the processor performs the method in any one of thetwenty-first aspect or the possible implementations of the twenty-firstaspect.

According to a twenty-fourth aspect, a computer readable storage mediumis provided, configured to store a computer program, where the computerprogram includes an instruction used to perform the method in any one ofthe twenty-first aspect or the possible implementations of thetwenty-first aspect.

According to a twenty-fifth aspect, a communications system is provided,where the communications system includes user equipment, and the userequipment includes the user equipment in any one of the first aspect orthe possible implementations of the first aspect.

According to a twenty-sixth aspect, a communications system is provided,where the communications system includes a base station and userequipment, and the user equipment is the user equipment in any one ofthe second aspect or the possible implementations of the second aspector the user equipment in any one of the third aspect or the possibleimplementations of the third aspect.

According to a twenty-seventh aspect, a communications system isprovided, where the communications system includes user equipment, andthe user equipment includes the user equipment in any one of the ninthaspect or the possible implementations of the ninth aspect.

According to a twenty-eighth aspect, a communications system isprovided, where the communications system includes a device, and thedevice is the device in any one of the twenty-second aspect or thepossible implementations of the twenty-second aspect or the device inany one of the twenty-third aspect or the possible implementations ofthe twenty-third aspect. Based on the foregoing technical solutions, onone hand, different base sequences are determined based on differentfrequency-domain resource groups, and reference signal sequences aregenerated based on the base sequences and are mapped to correspondingtime-frequency resources, to help different UEs implement RSorthogonality in different bandwidths, thereby improving RS resourcemultiplexing efficiency, and implementing RS resource multiplexing of aplurality of UEs. On the other hand, different frequency-domain resourcegroups are allocated to different user equipments to send referencesignals, so that RS resource multiplexing efficiency is improved, and RSresource multiplexing of a plurality of UEs is implemented.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a schematic diagram of a reference signal transmission methodaccording to an embodiment of the present application;

FIG. 2 is a schematic diagram of RS resource multiplexing of a pluralityof users in an uplink according to an embodiment of the presentapplication;

FIG. 3 is a schematic diagram of a reference signal transmission methodaccording to an embodiment of the present application;

FIG. 4 is a schematic diagram of a reference signal transmission methodaccording to an embodiment of the present application;

FIG. 5 is a schematic diagram of a frequency-domain resource and afrequency-domain comb according to an embodiment of the presentapplication;

FIG. 6 is a schematic diagram of multiplexing an RS resource by aplurality of user equipments by using a method of combining FDM and CDMaccording to an embodiment of the present application;

FIG. 7 is a schematic diagram of another reference signal transmissionmethod according to an embodiment of the present application;

FIG. 8 is a schematic structural diagram of a physical apparatusaccording to an embodiment of the present application;

FIG. 9 is a schematic diagram of still another reference signaltransmission method according to an embodiment of the presentapplication; and

FIG. 10 is another schematic diagram of RS resource multiplexing of aplurality of users in an uplink according to an embodiment of thepresent application.

DETAILED DESCRIPTION

The following describes technical solutions in embodiments of thepresent application with reference to accompanying drawings.

It should be understood that, the technical solutions of the embodimentsof the present application may be applied to various communicationssystems, such as: a Global System for Mobile Communications (GSM), aCode Division Multiple Access (CDMA) system, a Wideband Code DivisionMultiple Access (WCDMA) system, a general packet radio service (GPRS)system, a Long Term Evolution (LTE) system, an LTE frequency divisionduplex (FDD) system, an LTE time division duplex (TDD) system, and aUniversal Mobile Telecommunications System (UMTS).

A terminal may be referred to as user equipment (UE), a user, or thelike. The terminal may communicate with one or more core networks byusing a radio access network (RAN). The terminal may be a mobileterminal, such as a mobile phone (also referred to as a “cellular”phone) and a computer with a mobile terminal. For example, the terminalmay be a portable, pocket-sized, handheld, computer built-in, orin-vehicle mobile apparatus, which exchanges voice and/or data with theradio access network.

For ease of understanding the embodiments of the present application,some elements that are introduced in descriptions of the embodiments ofthe present application are described herein first.

An air interface resource is defined as air interface time-domain andfrequency-domain resources, and is usually represented by a resourceelement (RE), a resource block (RB), a symbol, a subcarrier, and atransmission time interval (TTI). The air interface resource may bedivided from perspectives of frequency domain and time domain. A minimumresource granularity of frequency domain division is a subcarrier, and aminimum resource granularity of time domain division is a symbol.

One RE represents a resource of one subcarrier within one symbol time,and each RE may carry specific information. N symbols form one TTI interms of time. M subcarriers in one TTI are combined into one RB.

To ensure requirements of low latency and high reliability of a URLLCservice, a URLLC uplink service may flexibly occupy a physical resourceof an MBB uplink service in a short TTI in a preemption or reservationmanner. The short TTI herein is a shorter subframe in terms of time.Currently, one LTE subframe length is 1 ms, and a subframe of the shortTTI has a length shorter than 1 ms, for example, may be 0.125 ms oranother time length. In the short TTI, because a quantity of time-domainsymbols is reduced, in an uplink, there are few symbols that can be usedfor transmission of an uplink data demodulation RS, and there may beonly one symbol. Therefore, in a scenario with RSs of a plurality ofusers, time-frequency resources occupied by two user equipments mayoverlap. In addition, a scenario of an orthogonal/quasi-orthogonal pilotdesign between different cells and a scenario in which paired UEs inUL/DL MU-MIM0 occupy different bandwidths (the bandwidths partlyoverlap) face a similar technical problem. How to implement RS resourcemultiplexing of a plurality of users is a technical problem to beresolved in the embodiments of the present application.

FIG. 1 is a schematic diagram of a reference signal transmission methodaccording to an embodiment of the present application. The method inFIG. 1 is performed by user equipment.

101. First user equipment determines at least one base sequencecorresponding to at least one frequency-domain resource group that is ona symbol carrying a reference signal and that is used to send thereference signal.

One frequency-domain resource group is corresponding to one type of basesequence, and each frequency-domain resource group includes a pluralityof subcarriers that have a same quantity.

It should be understood that, in this embodiment of the presentapplication, one frequency-domain resource group may include a pluralityof frequency-domain subcarriers, and each frequency-domain resourcegroup includes a same quantity of subcarriers.

It should be understood that, in this embodiment of the presentapplication, the symbol used to carry the reference signal may includeone or more symbols.

It should be understood that one base sequence is not equivalent to onetype of base sequence. One base sequence indicates a base sequencequantity, and one type of base sequence indicates a base sequence type.

The first user equipment sends the reference signal on the at least onefrequency-domain resource group, each frequency-domain resource groupsends one reference signal sequence of the reference signal, and atleast one reference signal sequence sent on the at least onefrequency-domain resource group forms the reference signal. Eachreference signal sequence is generated by using one base sequence, andthe first user equipment needs to determine that a quantity of basesequences is the same as a quantity of frequency-domain resource groups.One frequency-domain resource group is corresponding to one type of basesequence, different frequency-domain resource groups may use a same basesequence or different base sequences, and a total quantity of types ofthe at least one base sequence is less than or equal to a quantity ofthe at least one base sequence. It should be understood that onefrequency-domain resource group is corresponding to one type of basesequence, and a frequency-domain resource group type may be in aone-to-one correspondence with a base sequence type, or may be in amultiple-to-one correspondence with the base sequence type. For example,one frequency-domain resource group index is corresponding to an indexof one type of base sequence, and the frequency-domain resource groupindex may be related to the base sequence index. In a specific example,frequency-domain resource group indexes 1, 2, and 3 are corresponding toa base sequence index 1, and a frequency-domain resource group index 4is corresponding to a base sequence index 2. In other words, differentfrequency-domain resource groups may use a same base sequence ordifferent base sequences. A total quantity of types of the at least onebase sequence corresponding to the at least one frequency-domainresource group used to send the reference signal is less than or equalto a quantity of the at least one base sequence.

In one embodiment, a correspondence between the frequency-domainresource group and the base sequence is pre-defined.

In one embodiment, a correspondence between the frequency-domainresource group and the base sequence is sent by a base station to theuser equipment.

102. The first user equipment generates the reference signal based onthe at least one base sequence, and maps the reference signal to atime-frequency resource whose time domain is the symbol and whosefrequency domain is the at least one frequency-domain resource group.

It should be understood that, the first user equipment generates thereference signal based on the base sequence, each base sequence is usedto generate one reference signal sequence of the reference signal, andall generated reference signal sequences form the reference sequence.

It should be understood that after generating the reference signal, thefirst user equipment may map the reference signal to the time-frequencyresource for sending the reference signal. Time domain of thetime-frequency resource is the symbol (the symbol that carries thereference signal), and frequency domain is the at least onefrequency-domain resource group.

It should be understood that, after mapping the reference signal to thetime-frequency resource, the first user equipment may send the referencesignal.

In this embodiment of the present application, different base sequencesare determined based on different frequency-domain resource groups, andthe reference signal is generated based on the base sequences, and ismapped to a corresponding time-frequency resource. This helps implementorthogonality of RSs of different UEs in different bandwidths, therebyimproving RS resource multiplexing efficiency, and implementing RSresource multiplexing of a plurality of users.

In one embodiment, if the first user equipment and second user equipmentmultiplex a third frequency-domain resource group on the symbol, cyclicshifts used by the user equipment and the second user equipment togenerate reference signal sequences based on a third base sequence aredifferent. The third frequency-domain resource group is one of the atleast one frequency-domain resource group, and the third base sequenceis a base sequence corresponding to the third frequency-domain resourcegroup.

In this embodiment of the present application, different cyclic shiftsare configured for base sequences of different UEs on a samefrequency-domain resource group, so that orthogonality of RSs of UEs indifferent bandwidths can be implemented on a same frequency-domainresource group. Therefore, RS resource multiplexing efficiency can beimproved, and RS resource multiplexing of a plurality of users can beimplemented.

Further, specific implementation of operation 101 is: The first userequipment determines a first base sequence corresponding to a firstfrequency-domain resource group, and determines a second base sequencecorresponding to a second frequency-domain resource group. In this case,specific implementation of operation 102 is: The first user equipmentgenerates a first reference signal sequence of the reference signalbased on the first base sequence, and maps the first reference signalsequence to a time-frequency resource whose time domain is the symboland whose frequency domain is the first frequency-domain resource group;and the first user equipment generates a second reference signalsequence of the reference signal based on the second base sequence, andmaps the second reference signal sequence to a time-frequency resourcewhose time domain is the symbol and whose frequency domain is the secondfrequency-domain resource group.

In one embodiment, a cyclic shift used by the first user equipment togenerate the first reference signal sequence is different from a cyclicshift used to generate the second reference signal sequence.

Alternatively, In one embodiment, a cyclic shift used by the first userequipment to generate the first reference signal sequence is the same asa cyclic shift used to generate the second reference signal sequence.

Further, when the cyclic shift used by the first user equipment togenerate the first reference signal sequence is the same as the cyclicshift used to generate the second reference signal sequence, the cyclicshift is notified by the base station to the user equipment, or thecyclic shift is determined by the user equipment based on aconfiguration parameter. The configuration parameter includes one ormore of a UE-specific configuration parameter, a time domain-specificconfiguration parameter, a cell-specific configuration parameter, and afrequency domain-specific configuration parameter, and the configurationparameter cannot include only the cell-specific configuration parameteror the frequency domain-specific configuration parameter.

The method in this embodiment of the present application is furtherdescribed with reference to specific embodiments below.

FIG. 2 is a schematic diagram of RS resource multiplexing of a pluralityof users in an uplink according to an embodiment of the presentapplication. As shown in FIG. 2, an RB includes four frequency-domainresource groups: N to N+3 in frequency domain, and seven symbols: 0 to 6in time domain. UE 1 sends data on time-frequency resources whose timedomains are the symbol 2 and whose frequency domains are thefrequency-domain resource groups N to N+3, UE 2 sends data ontime-frequency resources whose time domains are the symbols 4 and 5 andwhose frequency domains are the frequency-domain resource groups N andN+1, and UE 3 sends data on time-frequency resources whose time domainsare the symbols 4 and 5 and whose frequency domains are thefrequency-domain resource groups N+2 and N+3. The UE 1, the UE 2, andthe UE 3 send reference signals on the symbol 3 (a time-frequencyresource shown in a gray grid). The UE 1 sends the reference signal ontime-frequency resources whose time domains are the symbol 3 and whosefrequency domains are the frequency-domain resource groups N to N+3, theUE 2 sends the reference signal on time-frequency resources whose timedomains are the symbol 3 and whose frequency domains are thefrequency-domain resource groups N and N+1, and the UE 3 sends thereference signal on time-frequency resources whose time domains are thesymbol 3 and whose frequency domains are the frequency-domain resourcegroups N+2 and N+3.

In this embodiment of the present application, one reference signal mayinclude one reference signal sequence generated based on one basesequence, or may include a plurality of reference signal sequencesgenerated based on a plurality of base sequences.

In this embodiment of the present application, one frequency-domainresource group is corresponding to one type of base sequence, and aplurality of different frequency-domain resource groups may becorresponding to a same type of base sequence. Each frequency-domainresource group may include one or more subcarriers. A correspondencebetween a frequency-domain resource group and a base sequence, forexample, may be that a frequency-domain resource group index is relatedto a base sequence index. For example, frequency-domain resource groupindexes 1, 2, and 3 are corresponding to a base sequence index 1, and afrequency-domain resource group index 5 is corresponding to a basesequence index 2. It is assumed that the frequency-domain resourcegroups N, N+1, N+2, and N+3 in FIG. 2 are respectively corresponding tobase sequences N′, N′+1, N′+2, and N′+3.

In addition, it should be understood that the correspondence between afrequency-domain resource group and a base sequence may be specified ina protocol, or may be pre-defined, or may be notified by a base stationto user equipment by using a configuration message. This is not limitedin this embodiment of the present application.

For one UE, the UE uses, on an occupied frequency-domain resource group,a base sequence corresponding to the frequency-domain resource group togenerate a reference signal sequence of a reference signal, and maps thereference signal sequence to a time-frequency resource corresponding tothe frequency-domain resource group.

The UE 1 is used as an example. The UE separately generates referencesignal sequences N′, N′+1, N′+2, and N′+3 based on base sequences N,N+1, N+2, and N+3, and separately maps the reference signal sequences totime-frequency resources whose time domains are the symbol 3 and whosefrequency domains are the frequency-domain resource groups N, N+1, N+2,and N+3.

It should be understood that a cyclic shift used by the user equipmentto generate the reference signal sequence based on the base sequence maybe notified by the base station to the user equipment, or may bedetermined by the user equipment based on a configuration parameter. Theconfiguration parameter may include one or more of a UE-specificconfiguration parameter, a time domain-specific configuration parameter,a cell-specific configuration parameter, and a frequency domain-specificconfiguration parameter that are of the user equipment. It should benoted that the configuration parameter cannot include only thecell-specific configuration parameter or the frequency domain-specificconfiguration parameter.

Preferably, cyclic shifts used by same user equipment to generatereference signal sequences based on base sequences are the same. Whenthe cyclic shifts used by the same user equipment are the same, the basestation may notify the user equipment of only one type of cyclic shift,or the user equipment may determine only one type of cyclic shift basedon the configuration parameter.

In addition, on a same frequency-domain resource group, different userequipments use different cyclic shifts of a same base sequence togenerate respective reference signal sequences. For example, on thefrequency-domain resource group N, cyclic shifts used by the UE 1 andthe UE 2 to generate reference signal sequences by using the basesequence N are different.

A specific example of base sequences and cyclic shifts that are used byeach UE in FIG. 2 on each frequency-domain resource group is shown inTable 1.

TABLE 1 Frequency- Frequency- Frequency- Frequency- domain domain domaindomain resource resource resource resource group group group group N N +1 N + 2 N + 3 UE 1 Base N′ N′ + 1 N′ + 2 N′ + 3 sequence Cyclic K K K Kshift UE 2 Base N′ N′ + 1 N/A N/A sequence Cyclic K + 1 K + 1 N/A N/Ashift UE 3 Base N/A N/A N′ + 2 N′ + 3 sequence Cyclic N/A N/A K + 1 K +1 shift

As shown in Table 1, from a perspective of one UE, a same cyclic shiftof a plurality of base sequences may be used for an RS corresponding todata that is sent, so that overheads of base station-side controlsignaling can be greatly reduced.

In this embodiment of the present application, a time-frequency resourcegroup is used to implicitly indicate a base sequence used for generatinga reference signal, so that an RS resource multiplexing rate can beincreased, RS resource multiplexing of a plurality of user equipmentscan be implemented, and orthogonality between RSs of the plurality ofusers can further be ensured.

FIG. 3 is a schematic diagram of a reference signal transmission methodaccording to an embodiment of the present application. The method inFIG. 3 is performed by user equipment.

301. The user equipment receives downlink control signaling sent by abase station, where the downlink control signaling is used to indicate afrequency-domain resource group that is on a symbol carrying a referencesignal and that is used by the user equipment to send the referencesignal, and each frequency-domain resource group includes a plurality ofsubcarriers that have a same quantity.

In one embodiment, the downlink control signaling is a user-specificUE-specific configuration message.

302. The user equipment generates a reference signal sequence, and mapsthe reference signal sequence to a time-frequency resource whose timedomain is the symbol and whose frequency domain is the frequency-domainresource group.

In this embodiment of the present application, the user equipmentgenerates the reference signal based on the frequency-domain resourcegroup allocated by the base station, so that different user equipmentscan use different frequency-domain resources to send reference signals.Therefore, RS resource multiplexing efficiency can be improved, and RSresource multiplexing of a plurality of users can be implemented.

In one embodiment, the downlink control signaling carries an index of afrequency-domain comb. The method further includes: The user equipmentdetermines the frequency-domain resource group based on afrequency-domain resource occupied by the user equipment and thefrequency-domain comb, where the frequency-domain resource groupincludes a plurality of evenly spaced comb teeth (one comb tooth is onesubcarrier). The frequency-domain comb is used to obtain one subcarrierat an interval of N subcarriers from a continuous frequency-domainresource, to obtain a plurality of evenly spaced comb teeth(subcarriers). For a same frequency-domain resource (bandwidth),different available frequency-domain resources can be obtained by usingdifferent frequency-domain combs. Different frequency-domain combs areallocated to different users, so that user equipments can obtaindifferent frequency-domain resources in a same bandwidth, to sendreference signals.

In some embodiments, a comb structure may include M subcarriers in eachN subcarriers, where intervals between a plurality of M subcarriers areequal.

For example, when M is 2, the comb structure may include two subcarriersselected from each N subcarriers. The two subcarriers are consecutive,and intervals between every two subcarriers are equal.

FIG. 4 is a schematic diagram of a reference signal transmission methodaccording to an embodiment of the present application. The method inFIG. 4 is executed by user equipment.

401. The user equipment determines a frequency-domain resource thatcarries a reference signal of the user equipment, where thefrequency-domain resource is subcarriers that are distributed at equalintervals in frequency domain, and the reference signal is used for datachannel demodulation.

In some embodiments, an antenna port used for transmitting the referencesignal is related to an antenna port of a data channel that isdemodulated by using the reference signal. Generally, antenna portnumbers of the two antenna ports are the same.

402. The user equipment sends the reference signal to a base station onthe frequency-domain resource, or the user equipment receives, on thefrequency-domain resource, the reference signal sent by a base station.

In some embodiments, the subcarriers that are distributed at equalintervals in frequency domain may be frequency-domain comb teeth.

In some embodiments, a comb structure may include M subcarriers in eachN subcarriers, where intervals between a plurality of M subcarriers areequal.

In some embodiments, the user equipment may determine, based on a firstparameter, the frequency-domain resource that carries the referencesignal of the user equipment.

In some embodiments, the first parameter may be one or more of a userequipment-specific parameter, a time domain-specific parameter, acell-specific parameter, a frequency domain-specific parameter, and afirst configuration parameter from the base station.

It should be understood that a value of the user equipment-specificparameter can be used to identify a related parameter of the userequipment, for example, identifier information of the user equipment ora radio network temporary identifier (RNTI).

It should be understood that a value of the cell-specific parameter canbe used to identify a related parameter of a cell. For example, thecell-specific parameter may be identifier information of the cell.

It should be understood that a value of the time domain-specificparameter can be used to identify a time-domain location of a symbol ofthe reference signal. For example, the time domain-specific parametermay be a subframe number, a timeslot number, a mini-slot number, or asymbol.

It should be understood that a value of the frequency domain-specificparameter can be used to identify a frequency-domain location of thereference signal. For example, the frequency domain-specific parametermay be a resource block (RB) number, a resource block group (RBG)number, a subcarrier number, or a resource element group (REG) number.

In some embodiments, the first configuration parameter may be aparameter configured by the base station for the user equipment or atleast some or all of parameters configured by the base station for theuser equipment.

In some embodiments, the first configuration parameter may further be atleast some or all of parameters in configuration information configuredby the base station for the user equipment.

In some embodiments, the first configuration parameter is used todetermine the frequency-domain resource that carries the referencesignal of the user equipment.

In some embodiments, the first configuration parameter from the basestation may be one or more of an antenna port, a frequency domain startlocation of a transmission comb, a transmission comb index, and asubcarrier set index.

In some embodiments, the user equipment may determine, based on a secondparameter, a cyclic shift (CS) and/or an orthogonal cover code (OCC)used for a sequence of the reference signal. The second parameter is oneor more of a user equipment-specific parameter, a time domain-specificparameter, a cell-specific parameter, a frequency domain-specificparameter, and a second configuration parameter from the base station.

It should be understood that a value of the user equipment-specificparameter can be used to identify a related parameter of the userequipment, for example, identifier information of the user equipment ora radio network temporary identifier (RNTI).

It should be understood that a value of the cell-specific parameter canbe used to identify a related parameter of a cell. For example, thecell-specific parameter may be identifier information of the cell.

It should be understood that a value of the time domain-specificparameter can be used to identify a time-domain location of a symbol ofthe reference signal. For example, the time domain-specific parametermay be a subframe number, a timeslot number, a mini-slot number, or asymbol.

It should be understood that a value of the frequency domain-specificparameter can be used to identify a frequency-domain location of thereference signal. For example, the frequency domain-specific parametermay be a resource block (RB) number, a resource block group (RBG)number, a subcarrier number, or a resource element group (REG) number.

In some embodiments, the second configuration parameter may be aparameter configured by the base station for the user equipment or atleast some or all of parameters configured by the base station for theuser equipment.

In some embodiments, the second configuration parameter may further beat least some or all of parameters in configuration informationconfigured by the base station for the user equipment.

In some embodiments, the second configuration parameter is used todetermine the cyclic shift and/or the orthogonal cover code used for thesequence of the reference signal.

In some embodiments, the second configuration parameter may be one ormore of an antenna port, a frequency domain start location of atransmission comb, a transmission comb index, a subcarrier set index, acyclic shift identifier, and an orthogonal cover code identifier.

It should be understood that the first parameter and the secondparameter may be the same, or may be different, or the first parameterand the second parameter may partly overlap. For example, the firstparameter includes the second parameter or the second parameter includesthe first parameter, or some parameters in the first parameter and thesecond parameter are the same.

For example, FIG. 5 is a schematic diagram of a frequency-domainresource and a frequency-domain comb according to an embodiment of thepresent application. As shown in FIG. 5, a group of frequency-domaincomb teeth shown in a frequency-domain comb 1 may be obtained based onthe frequency-domain comb 1 (a first subcarrier is used as a startpoint, and one subcarrier is obtained at an interval of one subcarriersubsequently), and a group of frequency-domain comb teeth shown in afrequency-domain comb 2 may be obtained based on the frequency-domaincomb 2 (a second subcarrier is used as a start point, and one subcarrieris obtained at an interval of one subcarrier subsequently). As shown inFIG. 5, for a same frequency-domain resource (frequency-domain resource1), different frequency-domain resource groups may be obtained based ondifferent frequency-domain combs.

Further, if the user equipment and second user equipment occupy a samefrequency-domain resource, frequency-domain combs used by the userequipment and the second user equipment are different.

If the user equipment and the second user equipment occupy differentfrequency-domain resources, frequency-domain combs used by the userequipment and the second user equipment may be the same or may bedifferent, provided that different user equipments use differentfrequency-domain combs on an overlapped frequency-domain resource.

In an implementation of this embodiment of the present application, themethod further includes: The user equipment determines a base sequencebased on a frequency-domain comb, and generating the reference signalsequence based on the base sequence, where the frequency-domain comb iscorresponding to one type of base sequence. There may be amultiple-to-one or one-to-one mapping correspondence between thefrequency-domain comb and the base sequence.

In one embodiment, the correspondence between the frequency-domain comband the base sequence is pre-defined.

In one embodiment, the correspondence between the frequency-domain comband the base sequence is sent by the base station to the user equipment.

In another embodiment, the user equipment may use a manner of generatingthe reference signal sequence based on the base sequence in the existingFDM technology. For specific implementation, refer to the prior art, anddetails are not described herein in this embodiment of the presentapplication.

In some embodiments, when there are a plurality of user equipments in anetwork, reference signals of the plurality of user equipments need tobe orthogonal or quasi-orthogonal, and frequency-domain resources of theuser equipments are the same or partly overlapped, an RS resource may bemultiplexed by using a method of frequency division multiplexing (FDM)or combining FDM and code division multiplexing (CDM). A comb structuremay be used for FDM, and a CS, an OCC, or a combination thereof may beused for CDM.

It should be understood that when the reference signals are orthogonal,it may be considered that sequences of the reference signals arecompletely uncorrelated. When the reference signals arequasi-orthogonal, there is a specific correlation between thequasi-orthogonal reference signals, but the correlation is relativelylow.

For another example, FIG. 6 is a schematic diagram of multiplexing an RSresource by a plurality of user equipments by using a method ofcombining FDM and CDM according to an embodiment of the presentapplication. As shown in FIG. 6, frequency-domain resources of userequipment 2, user equipment 3, and user equipment 1 partly overlap, anda frequency-domain resource of user equipment 4 partly overlaps witheach of the frequency-domain resources of the user equipment 1, 2, and3. In this case, if there are only two comb teeth in a method of FDM,RSs of the four user equipments cannot be orthogonal by using only thetwo comb teeth, and the RSs of the four user equipments can beorthogonal with each other in a multiplexing manner of combining FDM andCDM. As shown in FIG. 6, the user equipment 1 uses a method of combing acomb 1 with a first CS or a first OCC; the user equipment 2 uses amethod of combing a comb 2 with the first CS or the first OCC; the userequipment 3 uses a method of combing the comb 2 with the first CS or thefirst OCC; and the user equipment 4 uses a method of combining the comb1 with a second CS or a second OCC. In this way, the RSs of the fouruser equipments are orthogonal to each other by using a frequency domainand code domain multiplexing method.

The plurality of user equipments in this embodiment of the presentapplication are not limited to a same cell. The user equipments may belocated in a same cell, or may be located in different cells, anddirections in which the user equipments send data may be the same or maybe different, to be specific, the plurality of user equipments may beused for uplink or downlink, or some of the user equipments are used foruplink, and some user equipments are used for downlink. The solution inthis embodiment may be used when the RSs of the plurality of userequipments need to be orthogonal or quasi-orthogonal in an actualnetwork.

The user equipment may determine, by using an antenna port configured bythe base station to be used for an RS of the user equipment, a combtooth used for the RS; or by using an identifier of a transmission combtooth configured by the base station for a user, or by using a methodsimilar to a sounding reference signal (SRS) indication method, the basestation indicates a frequency domain start location of the comb, and theuser equipment determines, based on the frequency domain start location,the comb tooth for use. In addition, the base station may further usedifferent comb teeth as some subcarrier sets, and indicate, byconfiguring a subcarrier set sequence number for the user equipment, acomb tooth occupied by the user equipment.

The CS and/or the OCC used for the RS sequence of the user equipment maybe related to one or more of parameters such as an antenna port of theRS, a transmission comb, a frequency domain start location, and asubcarrier set sequence number. For example, it is predefined that theantenna port of the RS, the transmission comb, the frequency domainstart location of the comb, or the subcarrier set sequence number is ina one-to-one correspondence with an identifier of the CS and/or the OCC.In some scenarios, the base station may directly configure theidentifier of the CS and/or the OCC used for the RS sequence. In thiscase, the identifier of the CS and/or the OCC may be different from theidentifier that is of the CS and/or the OCC and that is corresponding tothe antenna port of the RS, the transmission comb, the frequency domainstart location, or the subcarrier set sequence number.

In addition to the foregoing parameters, the comb tooth used for the RSand the CS and/or the OCC used for the RS sequence that are determinedby the user equipment may further be related to one or more of a userequipment-specific parameter, a time domain-specific parameter, acell-specific parameter, a network side device-specific parameter, afrequency domain-specific parameter, and a network side configurationparameter. FIG. 7 is a schematic diagram of a reference signaltransmission method according to an embodiment of the presentapplication. The method in FIG. 7 is performed by a base station.

701. The base station sends downlink control signaling to userequipment, where the downlink control signaling is used to indicate afrequency-domain resource group that is on a symbol carrying a referencesignal and that is used by the user equipment to send the referencesignal, and each frequency-domain resource group includes a plurality ofsubcarriers that have a same quantity.

702. The base station receives, on the frequency-domain resource group,a reference signal sent by the user equipment.

In this embodiment of the present application, the base stationallocates the frequency-domain resource group to the user equipment, togenerate the reference signal, so that different user equipments can usedifferent frequency-domain resources to send reference signals.Therefore, RS resource multiplexing efficiency can be improved, and RSresource multiplexing of a plurality of users can be implemented.

In one embodiment, the downlink control signaling carries afrequency-domain comb index, and the frequency-domain comb index is usedto determine the frequency-domain resource group in combination with afrequency-domain resource of the user equipment. The frequency-domainresource group includes a plurality of evenly spaced comb teeth (onecomb tooth is one subcarrier).

In one embodiment, the frequency-domain comb is corresponding to onetype of base sequence, and the frequency-domain comb index is furtherused by the user equipment to determine a base sequence used to generatea reference signal sequence. There may be a multiple-to-one orone-to-one correspondence between the frequency-domain comb and the basesequence.

In one embodiment, the base station sends the downlink control signalingby using a UE-specific message or the like.

An embodiment of the present application further discloses userequipment 1, configured to perform the method performed by the firstuser equipment in the embodiment shown in FIG. 1. Specifically, the userequipment 1 may include units configured to perform the method performedby the first user equipment in the embodiment shown in FIG. 1.

An embodiment of the present application further discloses userequipment 2, configured to perform the method performed by the userequipment in the embodiment shown in FIG. 3. Specifically, the userequipment 2 may include units configured to perform the method performedby the user equipment in the embodiment shown in FIG. 3.

An embodiment of the present application further discloses userequipment 3, configured to perform the method performed by the userequipment in the embodiment shown in FIG. 4. Specifically, the userequipment 3 may include units configured to perform the method performedby the user equipment in the embodiment shown in FIG. 4.

An embodiment of the present application further discloses a basestation 1, configured to perform the method performed by the basestation in the embodiment shown in FIG. 7. Specifically, the basestation 1 may include units configured to perform the method performedby the base station in the embodiment shown in FIG. 7.

An embodiment of the present application further provides user equipment4. A schematic structural diagram of a physical apparatus of the userequipment 4 may be a physical apparatus 800 in FIG. 8, and the physicalapparatus includes: a processor 802, a memory 803, a transmitter 801,and a receiver 804.

The receiver 804, the transmitter 801, the processor 802, and the memory803 are connected to each other by using a bus 806. The bus 806 may bean ISA bus, a PCI bus, an EISA bus, or the like. The bus may beclassified into an address bus, a data bus, a control bus, and the like.For ease of indication, the bus is indicated by using only onedouble-headed arrow in FIG. 8. However, it does not mean that there isonly one bus or only one type of bus. In specific application, thetransmitter 801 and the receiver 804 may be coupled to an antenna 805.

In some embodiments, the receiver 804, the transmitter 801, theprocessor 802, and the memory 803 may further communicate with eachother by using an internal link, to transmit a control and/or datasignal. The memory 803 is configured to store a program. Specifically,the program may include program code, and the program code includes acomputer operation instruction. The memory 803 may include a read-onlymemory and a random access memory, and provide an instruction and datafor the processor 802. The memory 803 may include a high-speed randomaccess memory (RAM), or may further include a non-transitory memory suchas at least one magnetic disk storage.

The processor 802 is configured to execute the program stored in thememory 803.

Specifically, in the user equipment 4, the processor 802 may beconfigured to perform the method in the embodiment shown in FIG. 1, andimplement functions of the first user equipment in the embodiment shownin FIG. 1.

The processor 802 may be an integrated circuit chip and has a signalprocessing capability. In an implementation process, operations in theforegoing method may be completed by using an integrated logic circuitof hardware in the processor 802 or an instruction in a form ofsoftware. The processor 802 may be a general purpose processor,including a central processing unit (CPU), a network processor (NP), orthe like; or may be a digital signal processor (DSP), anapplication-specific integrated circuit (ASIC), a field programmablegate array (FPGA) or another programmable logic device, a discrete gateor transistor logic device, or a discrete hardware assembly. Theprocessor 802 may implement or perform the methods, the operations, andlogical block diagrams that are disclosed in the embodiments of thepresent application. The general purpose processor may be amicroprocessor, or the processor may be any conventional processor orthe like. Operations of the methods disclosed with reference to theembodiments of the present application may be directly performed andcompleted by using a hardware decoding processor, or may be performedand completed by using a combination of hardware and software modules inthe decoding processor. The software module may be located in a maturestorage medium in the field, such as a random access memory, a flashmemory, a read-only memory, a programmable read-only memory, anelectrically-erasable programmable memory, or a register. The storagemedium is located in the memory 803. The processor 802 reads informationin the memory 803, and completes the operations of the foregoing methodsin combination with hardware of the processor.

An embodiment of the present application further provides user equipment5. A schematic structural diagram of a physical apparatus of the userequipment 5 may be shown in FIG. 8, and physical units included in theuser equipment 5 are similar to those of the user equipment 4. Detailsare not described again.

Specifically, in the user equipment 5, the processor 802 may beconfigured to perform the method in the embodiment shown in FIG. 3, andimplement functions of the user equipment in the embodiment shown inFIG. 3.

An embodiment of the present application further provides user equipment6. A schematic structural diagram of a physical apparatus of the userequipment 6 may be shown in FIG. 8, and physical units included in theuser equipment 6 are similar to those of the user equipment 4. Detailsare not described again.

Specifically, in the user equipment 6, the processor 802 may beconfigured to perform the method in the embodiment shown in FIG. 4, andimplement functions of the user equipment in the embodiment shown inFIG. 4.

An embodiment of the present application further provides a base station2. A schematic structural diagram of a physical apparatus of the basestation 2 may be shown in FIG. 8, and physical units included in thebase station 2 are similar to those of the user equipment 4. Details arenot described again.

Specifically, in the base station 2, the processor 802 may be configuredto perform the method in the embodiment shown in FIG. 7, and implementfunctions of the base station in the embodiment shown in FIG. 7.

An embodiment of the present application provides a reference signaltransmission apparatus 1, and the apparatus includes a processor and amemory.

In one embodiment, the apparatus 1 further includes a receiver and atransmitter.

Specifically, in the apparatus 1, the memory is configured to storeprogram code, and the processor is configured to invoke the program codeto implement the method in the embodiment shown in FIG. 1.

An embodiment of the present application provides a reference signaltransmission apparatus 2, and the apparatus includes a processor and amemory.

In one embodiment, the apparatus 2 further includes a receiver and atransmitter.

Specifically, in the apparatus 2, the memory is configured to storeprogram code, and the processor is configured to invoke the program codeto implement the method in the embodiment shown in FIG. 3.

An embodiment of the present application provides a reference signaltransmission apparatus 3, and the apparatus includes a processor and amemory.

In one embodiment, the apparatus 3 further includes a receiver and atransmitter.

Specifically, in the apparatus 3, the memory is configured to storeprogram code, and the processor is configured to invoke the program codeto implement the method in the embodiment shown in FIG. 4.

An embodiment of the present application provides a reference signaltransmission apparatus 4, and the apparatus includes a processor and amemory.

In one embodiment, the apparatus 4 further includes a receiver and atransmitter.

Specifically, in the apparatus 4, the memory is configured to storeprogram code, and the processor is configured to invoke the program codeto implement the method in the embodiment shown in FIG. 7.

An embodiment of the present application further provides a computerreadable storage medium 1, where the computer readable storage mediumstores one or more programs, the one or more programs include aninstruction, and when executed by a portable electronic device thatincludes a plurality of application programs, the instruction enablesthe portable electronic device to perform the method in the embodimentshown in FIG. 1.

An embodiment of the present application further provides a computerreadable storage medium 2, where the computer readable storage mediumstores one or more programs, the one or more programs include aninstruction, and when executed by a portable electronic device thatincludes a plurality of application programs, the instruction enablesthe portable electronic device to perform the method in the embodimentshown in FIG. 3.

An embodiment of the present application further provides a computerreadable storage medium 3, where the computer readable storage mediumstores one or more programs, the one or more programs include aninstruction, and when executed by a portable electronic device thatincludes a plurality of application programs, the instruction enablesthe portable electronic device to perform the method in the embodimentshown in FIG. 4.

An embodiment of the present application further provides a computerreadable storage medium 4, where the computer readable storage mediumstores one or more programs, the one or more programs include aninstruction, and when executed by a portable electronic device thatincludes a plurality of application programs, the instruction enablesthe portable electronic device to perform the method in the embodimentshown in FIG. 7.

An embodiment of the present application further provides acommunications system, including a base station and user equipment. Theuser equipment may be the user equipment 1, the user equipment 2, or theuser equipment 3 in the foregoing embodiments, and the base station maybe the base station 1 or the base station 2 in the foregoingembodiments.

FIG. 9 is a schematic diagram of a reference signal transmission methodaccording to an embodiment of the present application. The method inFIG. 9 is performed by a first device. The first device may be userequipment or a network side device, such as a base station.

901. The first device determines at least one reference signalgeneration sequence corresponding to at least one frequency-domainresource group that is on a symbol carrying a reference signal and thatis used to send the reference signal.

One frequency-domain resource group is corresponding to one referencesignal generation sequence.

It should be understood that, in this embodiment of the presentapplication, one frequency-domain resource group may include a pluralityof frequency-domain subcarriers, and each frequency-domain resourcegroup may include a same quantity of subcarriers, or may includedifferent quantities of subcarriers.

It should be understood that, in this embodiment of the presentapplication, the symbol used to carry the reference signal may includeone or more symbols.

It should be understood that the reference signal generation sequencemay include different types of sequences, for example, a ZC sequence ora pseudo-random sequence, or may be another sequence that meets acorrelation requirement. This is not limited in this embodiment of thepresent application.

The first device sends the reference signal on the at least onefrequency-domain resource group. Each frequency-domain resource group isused to send one reference signal sequence of the reference signal, andat least one reference signal sequence sent on the at least onefrequency-domain resource group forms the reference signal. Eachreference signal sequence is generated by using one reference signalgeneration sequence, and the first device needs to determine that aquantity of reference signal generation sequences is the same as aquantity of frequency-domain resource groups. One frequency-domainresource group is corresponding to one reference signal generationsequence, and different frequency-domain resource groups may use a samereference signal generation sequence or different reference signalgeneration sequences. It should be understood that one frequency-domainresource group is corresponding to one reference signal generationsequence, and there may be a one-to-one or multiple-to-onecorrespondence between the frequency-domain resource group and thereference signal generation sequence. For example, one frequency-domainresource group index is corresponding to one reference signal generationsequence index, and the frequency-domain resource group index may berelated to the reference signal generation sequence index. In a specificexample, frequency-domain resource group indexes 1, 2, and 3 arecorresponding to a reference signal generation sequence index 1, and afrequency-domain resource group index 4 is corresponding to a referencesignal generation sequence index 2. In other words, a same referencesignal generation sequence or different reference signal generationsequences may be used for different frequency-domain resource groups.

In one embodiment, the reference signal generation sequence isdetermined by the first device based on a second parameter set, andparameters in the second parameter set include one or more of a userequipment-specific parameter, a time domain-specific parameter, acell-specific parameter, a network side device-specific parameter, afrequency domain-specific parameter, a network side configurationparameter, and a combination parameter. The combination parameter is acombination of a plurality of parameters in the user equipment-specificparameter, the time domain-specific parameter, the cell-specificparameter, the network side device-specific parameter, the frequencydomain-specific parameter, and the network side configuration parameter.

In another embodiment, the correspondence between the frequency-domainresource group and the reference signal generation sequence ispre-defined. For example, a mapping relationship table between thereference signal generation sequence and a frequency-domain resourcelocation of the frequency-domain resource group may be specified in aprotocol.

In still another embodiment, when the first device is user equipment,the correspondence between the frequency-domain resource group and thereference signal generation sequence is sent by a network side device tothe first user equipment.

902. The first device generates the reference signal based on the atleast one reference signal generation sequence, and maps the referencesignal to a time-frequency resource whose time domain is the symbol andwhose frequency domain is the at least one frequency-domain resourcegroup.

It should be understood that the first device generates the referencesignal based on the reference signal generation sequence, each referencesignal generation sequence is used to generate one reference signalsequence of the reference signal, and all generated reference signalsequences form the reference signal.

It should be understood that, after generating the reference signal, thefirst device may map the reference signal to the time-frequency resourcefor sending the reference signal. Time domain of the time-frequencyresource is the symbol (the symbol that carries the reference signal),and frequency domain is the at least one frequency-domain resourcegroup.

It should be understood that, after mapping the reference signal to thetime-frequency resource, the first device may send the reference signal.

In this embodiment of the present application, different referencesignal generation sequences are determined based on differentfrequency-domain resource groups, and the reference signal is generatedbased on the reference signal generation sequences, and is mapped to acorresponding time-frequency resource. This helps implement RSorthogonality/quasi-orthogonality for different devices in differentbandwidths, thereby improving RS resource multiplexing efficiency, andimplementing RS resource multiplexing of a plurality of devices.

In one embodiment, when both the first device and a second device mapreference signals to a time-frequency resource whose time domain is thesymbol and whose frequency domain is a third frequency-domain resourcegroup, cyclic shifts or orthogonal cover codes used by the first deviceand the second device to generate reference signals based on a thirdreference signal generation sequence are different. The thirdfrequency-domain resource group is one of the at least onefrequency-domain resource group, and the third reference signalgeneration sequence is a reference signal generation sequencecorresponding to the third frequency-domain resource group.

In one embodiment, the cyclic shift or the orthogonal cover code isdetermined by the first device based on a first parameter set, andparameters in the first parameter set include one or more of a userequipment-specific parameter, a time domain-specific parameter, acell-specific parameter, a network side device-specific parameter, afrequency domain-specific parameter, and a network side configurationparameter.

In another embodiment, when the first device is user equipment, thecyclic shift or the orthogonal cover code is notified to the firstdevice by a network side device connected to the first device.

In another embodiment, when both the first device and a second devicemap reference signals to a time-frequency resource whose time domain isthe symbol and whose frequency domain is a third frequency-domainresource group, a reference signal generation sequence corresponding tothe first device on the third frequency-domain resource group isdifferent from a reference signal generation sequence corresponding tothe second device on the third frequency-domain resource group.

For example, the third frequency-domain resource group is one of the atleast one frequency-domain resource group, a third reference signalgeneration sequence is the reference signal generation sequencecorresponding to the first device on the third frequency-domain resourcegroup, a fourth reference signal generation sequence is the referencesignal generation sequence corresponding to the second device on thethird frequency-domain resource group. Both the first device and thesecond device map the reference signals to the time-frequency resourcewhose time domain is the symbol and whose frequency domain is the thirdfrequency-domain resource group. In this case, the first device maygenerate the reference signal based on the third reference signalgeneration sequence, and the second device may generate the referencesignal based on the fourth reference signal generation sequence.

It should be understood that, the first device may be first userequipment, the second device may be second user equipment, and the firstuser equipment and the second user equipment may connect to/reside on asame network side device or different network side devices; or the firstdevice may be a first network side device, and the second device may bea second network side device; or the first device may be a first networkside device, the second device may be second user equipment, and anetwork side device to/on which the second user equipmentconnects/resides may be the same as or different from the first networkside device; or the first device may be first user equipment, the seconddevice may be a second network side device, and a network side deviceto/on which the first user equipment connects/resides may be the same asor different from the second network side device.

It should be understood that the network side device may be a devicethat can schedule and control the user equipment, such as an evolvedNodeB (eNB) in LTE or a transmission/reception point (TRP) in NR.

In an embodiment, the reference signal generation sequence is determinedby the first device based on a second parameter set, and parameters inthe second parameter set include one or more of a userequipment-specific parameter, a time domain-specific parameter, acell-specific parameter, a network side device-specific parameter, afrequency domain-specific parameter, a network side configurationparameter, and a combination parameter. The combination parameter is acombination of a plurality of parameters in the user equipment-specificparameter, the time domain-specific parameter, the cell-specificparameter, the network side device-specific parameter, the frequencydomain-specific parameter, and the network side configuration parameter.

In another embodiment, a correspondence between the frequency-domainresource group and the reference signal generation sequence ispre-defined.

In still another embodiment, when the first device is user equipment, acorrespondence between the frequency-domain resource group and thereference signal generation sequence is sent to the first device by anetwork side device connected to the first device.

In this embodiment of the present application, different cyclic shiftsor orthogonal cover codes are configured for reference signal generationsequences of different devices on a same frequency-domain resourcegroup, or different reference signal generation sequences are configuredfor different devices on a same frequency-domain resource group, so thatdevices that occupy different bandwidths for transmission implement RSorthogonality on a same frequency-domain resource group. Therefore, RSresource multiplexing efficiency can be improved, and RS resourcemultiplexing by a plurality of devices can be implemented.

Further, specific implementation of operation 901 is: The first devicedetermines a first reference signal generation sequence corresponding toa first frequency-domain resource group, and determines a secondreference signal generation sequence corresponding to a secondfrequency-domain resource group. In this case, specific implementationof operation 902 is: The first device generates the first referencesignal sequence of the reference signal based on the first referencesignal generation sequence, and maps the first reference signal sequenceto a time-frequency resource whose time domain is the symbol and whosefrequency domain is the first frequency-domain resource group; and thefirst user equipment generates the second reference signal sequence ofthe reference signal based on the second reference signal generationsequence, and maps the second reference signal sequence to atime-frequency resource whose time domain is the symbol and whosefrequency domain is the second frequency-domain resource group.

It should be understood that a cyclic shift or an orthogonal cover codeused by the first device to generate the first reference signal sequencemay be the same or different from a cyclic shift or an orthogonal covercode used to generate the second reference signal sequence.

The method in this embodiment of the present application is furtherdescribed with reference to specific embodiments below.

FIG. 10 is a schematic diagram of RS resource multiplexing of aplurality of devices according to an embodiment of the presentapplication. As shown in FIG. 10, an RB includes four frequency-domainresource groups: N to N+3 in frequency domain, and seven symbols: 0 to 6in time domain. A device 1 sends data on time-frequency resources whosetime domains are the symbol 2 and whose frequency domains are thefrequency-domain resource groups N to N+3, a device 2 sends data ontime-frequency resources whose time domains are the symbols 4 and 5 andwhose frequency domains are the frequency-domain resource groups N andN+1, and a device 3 sends data on time-frequency resources whose timedomains are the symbols 4 and 5 and whose frequency domains are thefrequency-domain resource groups N+2 and N+3. The device 1, the device2, and the device 3 send reference signals on the symbol 3 (atime-frequency resource shown in a gray grid). The device 1 sends thereference signal on time-frequency resources whose time domains are thesymbol 3 and whose frequency domains are the frequency-domain resourcegroups N to N+3, the device 2 sends the reference signal ontime-frequency resources whose time domains are the symbol 3 and whosefrequency domains are the frequency-domain resource groups N and N+1,and the device 3 sends the reference signal on time-frequency resourceswhose time domains are the symbol 3 and whose frequency domains are thefrequency-domain resource groups N+2 and N+3 .

In this embodiment of the present application, one reference signal mayinclude one reference signal sequence generated based on one referencesignal generation sequence, or may include a plurality of referencesignal sequences generated based on a plurality of reference signalgeneration sequences.

In this embodiment of the present application, one frequency-domainresource group is corresponding to one reference signal generationsequence, and frequency-domain resource groups in a plurality ofdifferent frequency-domain resource groups may be corresponding todifferent reference signal generation sequences, or may be correspondingto a same reference signal generation sequence. Each frequency-domainresource group may include one or more subcarriers. A correspondencebetween a frequency-domain resource group and a reference signalgeneration sequence, for example, may be that a frequency-domainresource group index is related to a reference signal generationsequence index. For example, frequency-domain resource group indexes 1,2, and 3 are corresponding to a reference signal generation sequenceindex 1, and a frequency-domain resource group index 5 is correspondingto a reference signal generation sequence index 2. It is assumed thatthe frequency-domain resource groups N, N+1, N+2, and N+3 in FIG. 10 arerespectively corresponding to reference signal generation sequences M0,M1, M2, and M3. M0, M1, M2, and M3 may be the same, and may be differentfrom each other, or may be partly the same.

In addition, it should be understood that a reference signal generationsequence used by a device on a specific frequency-domain resource groupmay be determined by the device based on a second parameter set.Parameters in the second parameter set include one or more of a userequipment-specific parameter, a time domain-specific parameter, acell-specific parameter, a network side device-specific parameter, afrequency domain-specific parameter, a network side configurationparameter, and a combination parameter. The combination parameter is acombination of a plurality of parameters in the user equipment-specificparameter, the time domain-specific parameter, the cell-specificparameter, the network side device-specific parameter, the frequencydomain-specific parameter, and the network side configuration parameter.Alternatively, the second parameter set may be specified in a protocol,or may be notified to the user equipment by a network side device whenthe device is user equipment. This is not limited in this embodiment ofthe present application.

For one device, the device uses, on an occupied frequency-domainresource group, a reference signal generation sequence corresponding tothe frequency-domain resource group to generate a reference signalsequence of a reference signal, and maps the reference signal sequenceto a time-frequency resource corresponding to the frequency-domainresource group.

The device 1 is used as an example. The device 1 separately generatesreference signal sequences based on the reference signal generationsequences M0, M1, M2, and M3, and separately maps the reference signalsequences to time-frequency resources whose time domains are the symbol3 and whose frequency domains are the frequency-domain resource groupsN, N+1, N+2, and N+3.

It should be understood that, when generating the reference signalsequences based on the reference signal generation sequences, the devicemay use a corresponding orthogonal parameter, to ensureorthogonality/quasi-orthogonality between reference signals of differentdevices. For example, when a used reference signal generation sequenceis a ZC sequence, the orthogonal parameter is a cyclic shift; or when aused reference signal generation sequence is a pseudo-random sequence,the orthogonal parameter is an orthogonal cover code. The usedorthogonal parameter may be determined by the device based on a firstparameter set. Parameters in the first parameter set include one or moreof a user equipment-specific parameter, a time domain-specificparameter, a cell-specific parameter, a network side device-specificparameter, a frequency domain-specific parameter, and a network sideconfiguration parameter. When the device is user equipment, the firstparameter set may be notified to the user equipment by a network sidedevice. This is not limited in this embodiment of the presentapplication.

Orthogonal parameters used by a same device to generate reference signalsequences based on reference signal generation sequences may be thesame, or may be different, and the device preferably uses a sameorthogonal parameter. When the orthogonal parameters used by the samedevice are the same, the device may determine a cyclic shift based onthe parameter. In this case, if the device is user equipment, thenetwork side device may notify the user equipment of only one orthogonalparameter.

On a same frequency-domain resource group, different devices may usedifferent orthogonal parameters of a same reference signal generationsequence to generate respective reference signal sequences. For example,on the frequency-domain resource group N, orthogonal parameters used bythe device 1 and the device 2 to generate reference signal sequences byusing the reference signal generation sequence M0 are different. Inaddition, on a same frequency-domain resource group, different devicesmay use different reference signal generation sequences to generaterespective reference signal sequences. For example, on thefrequency-domain resource group N, the device 1 and the device 2separately generate respective reference signal sequences by using thereference signal generation sequences M1 and M2.

Five specific examples of reference signal generation sequences andorthogonal parameters used by each device in FIG. 10 on eachfrequency-domain resource group are shown in Tables 2, 3, 4, 5, and 6.

TABLE 2 Frequency- Frequency- Frequency- Frequency- domain domain domaindomain resource resource resource resource group group group group N N +1 N + 2 N + 3 Device 1 Reference M0 M1 M2 M3 signal generation sequenceOrthogonal K0 K0 K0 K0 parameter Device 2 Reference M0 M1 N/A N/A signalgeneration sequence Orthogonal K1 K1 N/A N/A parameter Device 3Reference N/A N/A M2 M3 signal generation sequence Orthogonal N/A N/AK1/K2 K1/K2 parameter

TABLE 3 Frequency- Frequency- Frequency- Frequency- domain domain domaindomain resource resource resource resource group group group group N N +1 N + 2 N + 3 Device 1 Reference M0 M1 M2 M3 signal generation sequenceOrthogonal K0 K1 K2 K3 parameter Device 2 Reference M0 M1 N/A N/A signalgeneration sequence Orthogonal K4 K5 N/A N/A parameter Device 3Reference N/A N/A M2 M3 signal generation sequence Orthogonal N/A N/A K6K7 parameter

TABLE 4 Frequency- Frequency- Frequency- Frequency- domain domain domaindomain resource resource resource resource group group group group N N +1 N + 2 N + 3 Device 1 Reference M0 M0 M0 M0 signal generation sequenceOrthogonal K0 K0 K0 K0 parameter Device 2 Reference M0 M0 N/A N/A signalgeneration sequence Orthogonal K1 K1 N/A N/A parameter Device 3Reference N/A N/A M0 M0 signal generation sequence Orthogonal N/A N/AK1/K2 K1/K2 parameter

TABLE 5 Frequency- Frequency- Frequency- Frequency- domain domain domaindomain resource resource resource resource group group group group N N +1 N + 2 N + 3 Device 1 Reference M0 M1 M2 M3 signal generation sequenceDevice 2 Reference M4 M5 N/A N/A signal generation sequence Device 3Reference N/A N/A M6 M7 signal generation sequence

TABLE 6 Frequency- Frequency- Frequency- Frequency- domain domain domaindomain resource resource resource resource group group group group N N +1 N + 2 N + 3 Device 1 Reference M0 M0 M0 M0 signal generation sequenceDevice 2 Reference M1 M1 N/A N/A signal generation sequence Device 3Reference N/A N/A M2 M2 signal generation sequence

As shown in Table 2, from a perspective of one device, a same orthogonalparameter of a plurality of reference signal generation sequences may beused for an RS corresponding to data that is sent.

As shown in Table 3, from a perspective of one device, differentorthogonal parameters of a plurality of reference signal generationsequences may be used for an RS corresponding to data that is sent.

As shown in Table 4, from a perspective of one device, on differentfrequency-domain resource groups, a same reference signal generationsequence may be used for an RS corresponding to data that is sent.

As shown in Table 5, from a perspective of different devices, on a samefrequency-domain resource group, different reference signal generationsequences may be used for an RS corresponding to data that is sent. Froma perspective of one device, on different frequency-domain resourcegroups, different reference signal generation sequences may be used foran RS corresponding to data that is sent.

As shown in Table 6, from a perspective of different devices, on a samefrequency-domain resource group, different reference signal generationsequences may be used for an RS corresponding to data that is sent. Froma perspective of one device, on different frequency-domain resourcegroups, a same reference signal generation sequence may be used for anRS corresponding to data that is sent.

In this embodiment of the present application, a reference signalgeneration sequence used to generate a reference signal is correspondingto a frequency-domain resource group, so that an RS resourcemultiplexing rate can be increased, RS resource multiplexing of aplurality of devices can be implemented, andorthogonality/quasi-orthogonality between RSs of the plurality ofdevices can further be ensured.

An embodiment of the present application further discloses a device 1,configured to perform the method performed by the first device in theembodiment shown in FIG. 9. The device may include units configured toperform the method performed by the first device in the embodiment shownin FIG. 9.

Specifically, the device may include a determining unit and a signalgeneration unit. The determining unit is configured to determine atleast one reference signal generation sequence corresponding to at leastone frequency-domain resource group that is on a symbol carrying areference signal and that is used to send the reference signal, whereone frequency-domain resource group is corresponding to one referencesignal generation sequence. The signal generation unit is configured togenerate the reference signal based on the at least one reference signalgeneration sequence, and map the reference signal to a time-frequencyresource whose time domain is the symbol and whose frequency domain isthe at least one frequency-domain resource group.

In one embodiment, when both the first device and a second device mapreference signals to a time-frequency resource whose time domain is thesymbol and whose frequency domain is a third frequency-domain resourcegroup, cyclic shifts or orthogonal cover codes used by the first deviceand the second device to generate the reference signals based on a thirdreference signal generation sequence are different. The thirdfrequency-domain resource group is one of the at least onefrequency-domain resource group, and the third reference signalgeneration sequence is a reference signal generation sequencecorresponding to the third frequency-domain resource group.

In one embodiment, the cyclic shift or the orthogonal cover code isdetermined by the first device based on a first parameter set, andparameters in the first parameter set include one or more of a userequipment-specific parameter, a time domain-specific parameter, acell-specific parameter, a network side device-specific parameter, afrequency domain-specific parameter, and a network side configurationparameter.

In another embodiment, when the first device is user equipment, thecyclic shift or the orthogonal cover code is notified to the firstdevice by a network side device connected to the first device.

In another embodiment, when both the first device and a second devicemap reference signals to a time-frequency resource whose time domain isthe symbol and whose frequency domain is a third frequency-domainresource group, a reference signal generation sequence corresponding tothe first device on the third frequency-domain resource group isdifferent from a reference signal generation sequence corresponding tothe second device on the third frequency-domain resource group.

In one embodiment, the determining unit is specifically configured to:determine a first reference signal generation sequence corresponding toa first frequency-domain resource group, and determine a secondreference signal generation sequence corresponding to a secondfrequency-domain resource group. The signal generation unit isspecifically configured to: generate a first reference signal sequenceof the reference signal based on the first reference signal generationsequence, and map the first reference signal sequence to atime-frequency resource whose time domain is the symbol and whosefrequency domain is the first frequency-domain resource group; andgenerate a second reference signal sequence of the reference signalbased on the second reference signal generation sequence, and map thesecond reference signal sequence to a time-frequency resource whose timedomain is the symbol and whose frequency domain is the secondfrequency-domain resource group.

In one embodiment, the reference signal generation sequence isdetermined by the device based on a second parameter set, and parametersin the second parameter set include one or more of a userequipment-specific parameter, a time domain-specific parameter, acell-specific parameter, a network side device-specific parameter, afrequency domain-specific parameter, a network side configurationparameter, and a combination parameter. The combination parameter is acombination of a plurality of parameters in the user equipment-specificparameter, the time domain-specific parameter, the cell-specificparameter, the network side device-specific parameter, the frequencydomain-specific parameter, and the network side configuration parameter.

In one embodiment, a correspondence between the frequency-domainresource group and the reference signal generation sequence ispre-defined.

In one embodiment, when the device is user equipment, a correspondencebetween the frequency-domain resource group and the reference signalgeneration sequence is sent to the device by a network side deviceconnected to the device.

An embodiment of the present application further discloses a device 2. Aschematic structural diagram of a physical apparatus of the device maybe a physical apparatus 800 in FIG. 8, and the physical apparatus 800includes: a processor 802, a memory 803, a transmitter 801, and areceiver 804.

The receiver 804, the transmitter 801, the processor 802, and the memory803 are connected to each other by using a bus 806. The bus 806 may bean ISA bus, a PCI bus, an EISA bus, or the like. The bus may beclassified into an address bus, a data bus, a control bus, and the like.For ease of indication, the bus is indicated by using only onedouble-headed arrow in FIG. 6. However, it does not mean that there isonly one bus or only one type of bus. In specific application, thetransmitter 801 and the receiver 804 may be coupled to an antenna 805.

In some embodiments, the receiver 804, the transmitter 801, theprocessor 802, and the memory 803 may further communicate with eachother by using an internal link to transmit a control and/or datasignal.

The memory 803 is configured to store a program. Specifically, theprogram may include program code, and the program code includes acomputer operation instruction. The memory 803 may include a read-onlymemory and a random access memory, and provide an instruction and datafor the processor 802. The memory 803 may include a high-speed RAMmemory, and may further include a non-transitory memory (non-transitorymemory), for example, at least one disk memory.

The processor 802 is configured to execute the program stored in thememory 803.

Specifically, in the device, the processor 802 is configured to performthe following method:

determining at least one reference signal generation sequencecorresponding to at least one frequency-domain resource group that is ona symbol carrying a reference signal and that is used to send thereference signal, where one frequency-domain resource group iscorresponding to one reference signal generation sequence; and

generating the reference signal based on the at least one referencesignal generation sequence, and mapping the reference signal to atime-frequency resource whose time domain is the symbol and whosefrequency domain is the at least one frequency-domain resource group.

The foregoing method that is performed by the first device and that isdisclosed in the embodiment in FIG. 9 of the present application may beapplied to the processor 802, or may be implemented by the processor802. The processor 802 may be an integrated circuit chip and has asignal processing capability. In an implementation process, operationsin the foregoing method may be completed by using an integrated logiccircuit of hardware in the processor 802 or an instruction in a form ofsoftware. The processor 802 may be a general purpose processor,including a CPU, a network processor (NP), and the like; or may be aDSP, an ASIC, an FPGA or another programmable logic device, a discretegate or a transistor logic device, or a discrete hardware component. Theprocessor 802 may implement or perform the methods, the operations, andlogical block diagrams that are disclosed in the embodiments of thepresent application. The general purpose processor may be amicroprocessor, or the processor may be any conventional processor orthe like. Operations of the methods disclosed with reference to theembodiments of the present application may be directly performed andcompleted by using a hardware decoding processor, or may be performedand completed by using a combination of hardware and software modules inthe decoding processor. The software module may be located in a maturestorage medium in the field, such as a random access memory, a flashmemory, a read-only memory, a programmable read-only memory, anelectrically-erasable programmable memory, or a register. The storagemedium is located in the memory 803. The processor 802 reads informationin the memory 803, and completes the operations of the foregoing methodsin combination with hardware of the processor.

In one embodiment, when both a first device and the second device mapreference signals to a time-frequency resource whose time domain is thesymbol and whose frequency domain is a third frequency-domain resourcegroup, cyclic shifts or orthogonal cover codes used by the first deviceand the second device to generate reference signals based on a thirdreference signal generation sequence are different. The thirdfrequency-domain resource group is one of the at least onefrequency-domain resource group, and the third reference signalgeneration sequence is a reference signal generation sequencecorresponding to the third frequency-domain resource group.

In one embodiment, the cyclic shift or the orthogonal cover code isdetermined by the first device based on a first parameter set, andparameters in the first parameter set include one or more of a userequipment-specific parameter, a time domain-specific parameter, acell-specific parameter, a network side device-specific parameter, afrequency domain-specific parameter, and a network side configurationparameter.

In another embodiment, when the first device is user equipment, thecyclic shift or the orthogonal cover code is notified to the firstdevice by a network side device connected to the first device.

In another embodiment, when both a first device and the second devicemap reference signals to a time-frequency resource whose time domain isthe symbol and whose frequency domain is a third frequency-domainresource group, a reference signal generation sequence corresponding tothe first device on the third frequency-domain resource group isdifferent from a reference signal generation sequence corresponding tothe second device on the third frequency-domain resource group.

In one embodiment, the reference signal generation sequence isdetermined by the first device based on a second parameter set, andparameters in the second parameter set include one or more of a userequipment-specific parameter, a time domain-specific parameter, acell-specific parameter, a network side device-specific parameter, afrequency domain-specific parameter, a network side configurationparameter, and a combination parameter. The combination parameter is acombination of a plurality of parameters in the user equipment-specificparameter, the time domain-specific parameter, the cell-specificparameter, the network side device-specific parameter, the frequencydomain-specific parameter, and the network side configuration parameter.

In another embodiment, a correspondence between the frequency-domainresource group and the reference signal generation sequence ispre-defined.

In still another embodiment, when the first device is user equipment, acorrespondence between the frequency-domain resource group and thereference signal generation sequence is sent to the first device by thenetwork side device connected to the first device.

Further, specific implementation of determining, by the processor 802,the at least one reference signal generation sequence corresponding tothe at least one frequency-domain resource group that is on the symbolcarrying the reference signal and that is used to send the referencesignal is: The processor 802 determines a first reference signalgeneration sequence corresponding to a first frequency-domain resourcegroup, and determines a second reference signal generation sequencecorresponding to a second frequency-domain resource group. In this case,specific implementation of generating, by the processor 802, thereference signal based on the at least one reference signal generationsequence, and mapping the reference signal to the time-frequencyresource whose time domain is the symbol and whose frequency domain isthe at least one frequency-domain resource group is: The processor 802generates a first reference signal sequence of the reference signalbased on the first reference signal generation sequence, and maps thefirst reference signal sequence to a time-frequency resource whose timedomain is the symbol and whose frequency domain is the firstfrequency-domain resource group; and generates a second reference signalsequence of the reference signal based on the second reference signalgeneration sequence, and maps the second reference signal sequence to atime-frequency resource whose time domain is the symbol and whosefrequency domain is the second frequency-domain resource group.

An embodiment of the present application further provides a computerreadable storage medium 4, where the computer readable storage mediumstores one or more programs, the one or more programs include aninstruction, and when executed by a portable electronic device thatincludes a plurality of application programs, the instruction enablesthe portable electronic device to perform the method in the embodimentshown in FIG. 9.

An embodiment of the present application further provides acommunications system, including the foregoing device 1 or device 2.

A person of ordinary skill in the art may be aware that, in combinationwith the examples described in the embodiments disclosed in thisspecification, units and algorithm operations may be implemented byelectronic hardware or a combination of computer software and electronichardware. Whether the functions are performed by hardware or softwaredepends on particular applications and design constraint conditions ofthe technical solutions. A person skilled in the art may use differentmethods to implement the described functions for each particularapplication, but it should not be considered that the implementationgoes beyond the scope of the embodiments of the present application.

It may be clearly understood by a person skilled in the art that, forthe purpose of convenient and brief description, for a detailed workingprocess of the foregoing system, apparatus, and unit, reference may bemade to a corresponding process in the foregoing method embodiments, anddetails are not described herein again.

In the several embodiments provided in this application, it should beunderstood that the disclosed system, apparatus, and method may beimplemented in other manners. For example, the described apparatusembodiment is merely an example. For example, the unit division ismerely logical function division and may be other division in actualimplementation. For example, a plurality of units or components may becombined or integrated into another system, or some features may beignored or not performed. In addition, the displayed or discussed mutualcouplings or direct couplings or communication connections may beimplemented by using some interfaces. The indirect couplings orcommunication connections between the apparatuses or units may beimplemented in electronic, mechanical, or other forms.

The units described as separate parts may or may not be physicallyseparate, and parts displayed as units may or may not be physical units,may be located in one position, or may be distributed on a plurality ofnetwork units. Some or all of the units may be selected based on actualrequirements to achieve the objectives of the solutions of theembodiments.

In addition, functional units in the embodiments of the presentapplication may be integrated into one processing unit, or each of theunits may exist alone physically, or two or more units are integratedinto one unit.

When the functions are implemented in the form of a software functionalunit and sold or used as an independent product, the functions may bestored in a computer-readable storage medium. Based on such anunderstanding, the technical solutions of the embodiments of the presentapplication essentially, or the part contributing to the prior art, orsome of the technical solutions may be implemented in a form of asoftware product. The computer software product is stored in a storagemedium, and includes several instructions for instructing a computerdevice (which may be a personal computer, a server, or a network device)to perform all or some of the operations of the methods described in theembodiments of the present application. The foregoing storage mediumincludes: any medium that can store program code, such as a USB flashdrive, a removable hard disk, a read-only memory (ROM), a random accessmemory (RAM), a magnetic disk, or an optical disc.

The foregoing descriptions are merely specific implementations of thepresent application, but are not intended to limit the protection scopeof the present application. Any variation or replacement readily figuredout by a person skilled in the art within the technical scope disclosedin the present application shall fall within the protection scope of thepresent application. Therefore, the protection scope of the presentapplication shall be subject to the protection scope of the claims.

1. A reference signal receiving method, comprising: receiving areference signal using a time-frequency resource whose time domainresource is a symbol and whose frequency domain resource comprises afirst frequency domain resource group and a second frequency domainresource group; wherein the reference signal is based on a first basesequence and a second base sequence, the first base sequencecorresponding to the first frequency domain resource group and thesecond base sequence corresponding to the second frequency domainresource group, and wherein the first frequency domain resource groupand the second frequency domain resource group correspond to twodifferent frequency-domain combs on the frequency domain resource thatis on the symbol.
 2. The method according to claim 1, wherein the firstfrequency-domain resource group and the second frequency-domain resourcegroup comprise a same quantity of subcarriers.
 3. The method accordingto claim 1, wherein: the reference signal comprises a first referencesignal sequence and a second reference signal sequence, the firstreference signal sequence corresponding to the first base sequence andthe second reference signal sequence corresponding to the second basesequence.
 4. The method according to claim 3, wherein a cyclic shiftused to generate the first reference signal sequence is the same as acyclic shift used to generate the second reference signal sequence.
 5. Areference signal transmission method, comprising: sending a referencesignal using a time-frequency resource whose time domain resource is asymbol and whose frequency domain resource comprises a first frequencydomain resource group and a second frequency domain resource group,wherein the reference signal is based on a first base sequence and thesecond base sequence, the first base sequence corresponding to a firstfrequency domain resource group and the second base sequencecorresponding to a second frequency domain resource group; wherein thefirst frequency domain resource group and the second frequency domainresource group correspond to different frequency domain combs on thefrequency domain resource that is on the symbol.
 6. The method accordingto claim 5, wherein the first frequency domain resource group and thesecond frequency domain resource group comprise a same quantity ofsubcarriers.
 7. The method according to claim 5, wherein a cyclic shiftused to generate the first reference signal sequence is the same as acyclic shift used to generate the second reference signal sequence. 8.An apparatus, comprising a processor and a memory, wherein the memorystores instructions which, when executed by the processor, cause theapparatus to: send a reference signal by using a time-frequency resourcewhose time domain resource is a symbol and whose frequency domainresource comprises a first frequency domain resource group and a secondfrequency domain resource group, wherein the reference signal is basedon a first base sequence and a second base sequence, the first basesequence corresponding to a first frequency domain resource group andthe second base sequence corresponding to a second frequency domainresource group; wherein the first frequency domain resource group andthe second frequency domain resource group correspond to differentfrequency domain combs on a frequency domain resource that is on thesymbol.
 9. The apparatus according to claim 8, wherein the firstfrequency domain resource group and the second frequency domain resourcegroup comprise a same quantity of subcarriers.
 10. The apparatusaccording to claim 8, wherein a cyclic shift used to generate the firstreference signal sequence is the same as a cyclic shift used to generatethe second reference signal sequence.
 11. The apparatus according toclaim 8, wherein: a correspondence between the first frequency domainresource group and the first base sequence and a correspondence betweenthe second frequency-domain resource group and the second base sequenceare pre-defined.
 12. The apparatus according to claim 8, wherein thememory stores further instructions which, when executed by theprocessor, cause the apparatus to: send a correspondence between thefirst frequency domain resource group and the first base sequence and acorrespondence between the second frequency domain resource group andthe second base sequence.
 13. The apparatus according to claim 8,wherein the apparatus is a base station.
 14. The apparatus according toclaim 8, wherein the apparatus is user equipment.
 15. The apparatusaccording to claim 8, wherein the reference signal comprises a firstreference signal sequence and a second reference signal sequence, thefirst reference signal sequence corresponding to the first base sequenceand the second reference signal sequence corresponding to the secondbase sequence.
 16. The apparatus according to claim 15, wherein a cyclicshift used to generate the first reference signal sequence is the sameas a cyclic shift used to generate the second reference signal sequence.17. The method according to claim 5, wherein the reference signalcomprises a first reference signal sequence and a second referencesignal sequence, the first reference signal sequence corresponding tothe first base sequence and the second reference signal sequencecorresponding to the second base sequence.
 18. The method according toclaim 17, wherein a cyclic shift used to generate the first referencesignal sequence is the same as a cyclic shift used to generate thesecond reference signal sequence.
 19. The method according to claim 5,wherein: a correspondence between the first frequency domain resourcegroup and the first base sequence and a correspondence between thesecond frequency-domain resource group and the second base sequence arepre-defined.
 20. The method according to claim 5, further comprisingsending a correspondence between the first frequency domain resourcegroup and the first base sequence and a correspondence between thesecond frequency domain resource group and the second base sequence.